Table 1.

Eligibility criteria

Inclusion criteria	Exclusion criteria
− Country and setting: Ethiopian rift valley	− The article did not contain original data or observations
− Study design: Cross-sectional	− Study subjects were not humans
− Measurement: The concentration of fluoride in ground water and prevalence of dental fluorosis	− Fluoride concentration was not measured or estimated
− Types of article: Peer-reviewed and published in English language	− Dental fluorosis was not reported using the three-severity level
− Publication year: up to December, 2018	− The mean and standard deviation of Fluoride concentration was not reported
− Undertook laboratory works: Reported type of laboratory tests and the respective result	− Being a review study
− Measurable outcomes: dental fluorosis (Dean’s index)	− Being none related to fluoride in ground water supplies and dental fluorosis